Python is more popular in the sense that it is often listed as a "nice to have" on many resumes, and is also often used by non-developers like DBAs, SysAdmins, biologists, & mathematicians.
But from a "build a new product" perspective, Python is losing to Ruby, Go, and JavaScript.
I didn't mean to hurt your feelings. I just thought your example proved that Python can be used for high performance apps. Dropbox once ran on it. They might have had problems but it was after they already experienced success.
My original comment was "Python is losing to Ruby, Go, and JavaScript". From purely a job market perspective I can't see why'd you'd invest time in learning Python over Ruby and JS. For non-blocking I/O people are going with JS instead of things like tornado. From a pure performance perspective, Go wins out over most/all interpreted languages.
Python is only winning a few niche markets like numerical computation, statistics. and biology...which most developers are not in. If you are trying to learn a language to get a job, you're probably not wanting to look at small niche industries to work in.
Of course you can build billion dollar companies in any language, but that wasn't the question or comment being discussed.
Given the fact that it is used beyond web programming to do just about everything where performance doesn't matter.